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What paging scheme is the "standard" for 128K models?Sinclair implemented an arrangement so that even numbered pages are non-contended, and odd numbered pages are contended (quoting from memory, haven't…
... 16384),a ;13 T
jr Loop ;12 T
[/code ... 25 T-states. The CPU clock is 17.7345 / 5 = ... to cover a complete bus cycle of this memory, which ... how long a memory bus cycle is at the Z80, ... more than 280ns (one CPU clock cycle). The RAMs used have ... -
Amazonia (BUGFIX)This is a bugfix for game [URL="http://www.worldofspectrum.org/infoseekid.cgi?id=0027280"]Amazonia[/URL], please add the following "known errors" des…
... /> 9ec7 21e99b ld hl,9be9h ; clock address
9eca 3e3c ld ... /> 9ec5 21e99b ld hl,9be9h ; clock address
9ec8 3e3b ld ... uppercase 'N'?
a4b6 20e7 jr nz,0a49fh ; otherwise wait for another ... -
Machine Code Routine of the weekHow about a thread that has a routine each week that is in [B]assembly language[/B] and is also described in great detail what the hell is going on …
... an INTA bus cycle. Useful, for ... or e
jr nz,LoopFillTable
ret ... or a
jr nz,LoopCreateHandlers
ret ... -
Tutorial - learn machine code in 30mins[B][I]Message from the moderators[/I] - bigjon has requested that readers' attention be drawn to a better version of this tutorial, one which is easi…
... l
dontmove
'jr nz' stands for jump relative if ... score'
To cycle round the game before ... br /> cp 255
jr nz, checkright
inc hl ... br /> or c
jr nz, wait
Save, assemble, ... br /> cp 255
jr nz, checkright
inc hl ... -
my tiny intros[IMG]http://pouet.net/screenshots/60493.png[/IMG] [url]http://pouet.net/prod.php?which=60493[/url] the following work will appear behind Demosplash…
... ld a, l;: or a: jr nz, bra1
dec a ... ixh: cp # 5b: jr nz, lp0
stu: jr mlp
[/PHP ... # 5b: jr nz, lp0; condition for completion of the cycle - when HL ... ld a, h: cp # 5b: jr nz, lp0
bit 2, ... (de), a
stu: jr mlp
[/PHP]
... -
Definitive list of games incompatible with +2A/+3 and of compatible versions (if any)I am trying to compile the definitive list of games which are incompatible with the +2A and the +3 and of their compatible versions, if they are pres…
... wait in neverending cycle. Games can be fixed - remove JR NZ,xx instrustions ... -
Definitive list of games incompatible with +2A/+3 and of compatible versions (if any)I am trying to compile the definitive list of games which are incompatible with the +2A and the +3 and of their compatible versions, if they are pres…
... wait in neverending cycle. Games can be fixed - remove JR NZ,xx instrustions ... -
The Disciple clone... doable?Hi. As a spectrum user in the 80's this was the dream interface all-in-one for me. I have a 48k+ and planning on get a 128K toast-rack later. Anyway…
... port are delayed by one cycle:
[CODE]
ROM ... (C),A
0 11CD JR #11CF
0 11CF LD ... DEC E
0 11D2 JR NZ,#11D1
[/CODE]
RCS (Reverse Computer Screen)[B]RCS[/B] ("Reverse Computer Screen", or simply SCR written backwards) is a small utility I'm about to release, that reorders bytes from the ZX-Spec…
... the RCS address every 8th cycle.
[CODE]Fast & ... /> E607 and $07
20F6 jr nz,lp2
78 ld a ... /> FE58 cp $58
20E7 jr nz,lp1
59 ld e ...SE Basic IV Buffy v4.1 source (WIP)I've been doing a major refactor on the SE Basic source and I'd appreciate a code review from anyone who has time to look at it. I've almost certainl…
... syntax_z ; checking syntax?
jr z, sound_1 ; jump if ... c ; timing loop
jr nz, be_h_and_l_lp ; 12 or 7 t ... 4, a ; half-cycle point?
jr nz, be_again ; jump if ... error if not in
jr nz, report_b ; short form
...Animated attribute revealA new challenge to solve next. I would like to create an animated attribute reveal in machine code by having my 768 byte attributes held in ram whic…
... ;size of 10-bit cycle + 1
push ... cp $5b
jr nc,SKIPDE ;skip if ... br /> dec c
jr nz,DELAY2
SKIPDE ... br /> or c
jr nz,LOOP10
ei
Simple text scrolling routine...I'm having trouble writing a very simple text scroller, the idea is to use the ROM printer routine to print 32 characters each time the routine is ca…
... in a,(c)
rra:jr c,demo
ret
dup 32;unroll cycle
rl(hl)
dec ...
dec b
jp nz,scroll_text
;out ... )
or a
jr nz,noloop
;if zero loop ... /> bw:and #80
jr z,nobit
set 0 ...Shadow of the Unicorn loader for +2A / +3hi, i have tried to load SotU with the [url="http://www.worldofspectrum.org/infoseekid.cgi?id=0023000"]RAM loader from Fraser Ross[/url], which is l…
... LD A,22 DEC A JR NZ,DELAY near the end of ... have to update my wait cycle calculations for the +3/+2A ... " and superfuous wait cycles in JR etc. are no longer present ...Definitive list of games incompatible with +2A/+3 and of compatible versions (if any)I am trying to compile the definitive list of games which are incompatible with the +2A and the +3 and of their compatible versions, if they are pres…
... wait in neverending cycle. Games can be fixed - remove JR NZ,xx instrustions ...ZX Dandanator! Mini - Cartridge system for SpectrumsHi All, I'd like to present a little HW I've developed during the last three months. It's aimed at providing a console-like usage experience for a…
... A=0 , 4 ts
JR NZ, SPPULSE ; Jump if pulses left ... ; 4ts
JR AFTERPUL ; Jump to end pulse cycle, 12 ts
cycle 13ts if cycle 8 if no cycle
NOP ...Running out of fingers in AssemblyDear all, Still trying to learn Assembly and have put a few routines together. However, as my routines become a little more involved I find myself…
... the architecture and cycle times of instructions; cycle times are never ... don't have to know cycle times to do that. It ... and as you get better cycle times will become important as ... zero
or l
jr nz, compute_lp
; write ...Must be missing the point - machine code... Hi Folks, Trying my hand at machine code again but falling at the first hurdle. I hand crafted the following to run at address 62000 and the co…
... screen byte (256 iterations)
JR NZ,Loop ; Loop if L not ... . It cuts the number of "JR NZ,Loop" instructions that have to ... executed in half and the clock cycles that you save can ... has to divide into the JR test value without a remainder ...1k Chess (was the 924 bytes thing!)Hi, I've decided to do a major rewrite of large parts of the code for the isometric Chess thing that I've been messing with. It got to the point, …
... jr nc,calc_lp1 ;
rrc d ;advance to next cycle ... :
dec a ;
jr nz,off_lp1 ;
save_sp:
...
